1. Commentary: prognosis revisited: a system for assigning periodontal prognosis;Kwok;J Periodontol,2007
2. Free autogenous gingival grafts. I. Principles of successful grafting;Sullivan;Periodontics,1968
3. The relationship between success of free gingival grafts and transplant thickness. Revascularization and shrinkage - a one year clinical study;Mörmann;J Periodontol,1981
4. Collagen as a basic element of the periodontium: immunohistochemical aspects in the human and animal. 1. Gingiva and alveolar bone;Romanos;Parodontologie,1990